Currently, polyarylene sulfide is representative engineering plastic, and is in great demand for high temperature and corrosive environment and electronic products due to high heat resistance, chemical resistance, flame resistance, and electric insulation. The major uses include computer accessories, automobile accessories, coating of the part contacting corrosive chemical materials, and industrial chemical resistant fiber, and the like.
Presently, polyphenylene sulfide (PPS) is the only commercially available polyarylene sulfide. According to the current commercial production process of PPS, p-dichlorobenzene (pDCB) and sodium sulfide are used as raw materials and reacted in a polar organic solvent such as N-methyl pyrrolidone, and the like. This method is known as a Macallum process, and the basic process is disclosed in U.S. Pat. Nos. 2,513,188 and 2,583,941, wherein some usable polar solvents are suggested but N-methylpyrrolidone (NMP, boiling Temp.; 202˜204° C.) is currently most commonly used. This process uses dichloro aromatic compounds as raw material, and sodium chloride (NaCl) is generated as a by-product.
Meanwhile, the PPS obtained in the Macallum process is washed and dried after polymerization reaction, and obtained in the form of powders. The powder PPS produced by these processes may generate considerable outgassing during a subsequent molding process or use, to cause property deterioration compared to immediately after polymerization. In addition, according to the above method, due to decomposition of PPS by residues, for example, moisture, residual reactant or residual organic solvent, and the like in the PPS, stains may be generated on the surface of the injection molded product. Also, to prevent generation of stains on the surface of the injection molded product, the surface of the injection mold should be cleaned often.
Meanwhile, since the outgas contains odor, it may contaminate environment in the work place.